[Bug c++/77384] Assembler error - std::forward(decimal64) already defined

[Bug c++/77384] Assembler error - std::forward(decimal64) already defined

[danielberger at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77384

--- Comment #3 from danielberger at gmail dot com ---
looks like this is now an ICE on trunk:

> <source>:9:63: error: Two symbols with same comdat_group are not linked by the same_comdat_group list.
>     9 | int main(void){return 0;/*stub provided by Compiler Explorer*/}
>       |                                                               ^
> _ZSt7forwardIDdEOT_RNSt16remove_referenceIS0_E4typeE/765 (constexpr _Tp&& std::forward(typename remove_reference<_Tp>::type&) [with _Tp = decimal::decimal64]) @0x7fa30f39b000
>   Type: function definition analyzed
>   Visibility: semantic_interposition no_reorder public weak comdat comdat_group:_ZSt7forwardIDdEOT_RNSt16remove_referenceIS0_E4typeE one_only visibility_specified
>   previous sharing asm name: 761
>   References: __gxx_personality_v0/768 (addr) 
>   Referring: 
>   Function flags: body
>   Called by: _ZNSt4pairIiDdEC2IiDdLb1EEEOT_OT0_/763 
>   Calls: 
> _ZSt7forwardIDdEOT_RNSt16remove_referenceIS0_E4typeE/761 (constexpr _Tp&& std::forward(typename remove_reference<_Tp>::type&) [with _Tp = <unnamed-float:64>]) @0x7fa30f087cc0
>   Type: function definition analyzed
>   Visibility: semantic_interposition no_reorder public weak comdat comdat_group:_ZSt7forwardIDdEOT_RNSt16remove_referenceIS0_E4typeE one_only visibility_specified
>   next sharing asm name: 765
>   References: __gxx_personality_v0/768 (addr) 
>   Referring: 
>   Function flags: body
>   Called by: _ZNSt4pairIiDdEC1IiDdLb1EEEOT_OT0_/754 
>   Calls: 
> <source>:9:63: internal compiler error: symtab_node::verify failed
> 0x217c229 internal_error(char const*, ...)
> 	???:0
> 0xbdf772 symtab_node::verify_symtab_nodes()
> 	???:0
> 0xbfbcaf symbol_table::finalize_compilation_unit()
> 	???:0
> Please submit a full bug report, with preprocessed source (by using -freport-bug).
> Please include the complete backtrace with any bug report.
> See <https://gcc.gnu.org/bugs/> for instructions.
> Compiler returned: 1

https://godbolt.org/z/Md56cT9e4

[Bug c++/77384] [11/12/13/14 Regression] Assembler error - std::forward(decimal64) already defined

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77384

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |5.5.0
           Keywords|                            |ABI, needs-bisection
            Summary|Assembler error -           |[11/12/13/14 Regression]
                   |std::forward(decimal64)     |Assembler error -
                   |already defined             |std::forward(decimal64)
                   |                            |already defined

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Hmm, the reduced testcase in comment #2 used to work in GCC 5.5.0.

[Bug c++/77384] Assembler error - std::forward(decimal64) already defined

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77384

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |5.5.0
      Known to work|5.5.0                       |
            Summary|[11/12/13/14 Regression]    |Assembler error -
                   |Assembler error -           |std::forward(decimal64)
                   |std::forward(decimal64)     |already defined
                   |already defined             |

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #2)
> This only happens for C++11 and later.
> 
> Modified testcase that's valid in C++98 too:

Oh I missed that. GCC 6 changed the default :).

[Bug c++/77384] Assembler error - std::forward(decimal64) already defined

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77384

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|needs-bisection             |
      Known to fail|                            |4.5.3

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Reduced testcase that where the issue happens for both C++98 and C++11+:
```
#include <decimal/decimal>
template<typename T1> int f(T1) {}
using std::decimal::decimal64;
int t = f(1.5dd);
int t1 = f(decimal64(1.5dd));
```